HOBOKEN -- The Hudson County Prosecutor's Office said late on Friday night that three teenage boys from Jersey City will be held in connection with the death of Ralph Santiago of Hoboken, whose body was found against a fence near Third and Jefferson streets in Hoboken during evening rush hour on Sept. 10.

Prosecutors told other news sources that the boys are 13 and 14 years old, and that it is believed that they were playing a game of "knockout" in which one boy leaps out in front of the victim and gives him a sucker punch. The other two boys allegedly had been following Santiago from behind.

What the boys may not have known was that Santiago was particularly vulnerable. He had suffered brain damage 27 years ago in the Bronx when he was struck from behind by assailants. After a long recovery in the hospital, he moved to Hoboken. He frequently ate at the homeless shelter with his mother.

Last week, the prosecutors released a video of three young men whom they said were "persons of interest" in the death.

The video appeared to be of the Second Street Light Rail station, just blocks from the site of Santiago's death. The boys, one with dreadlocks, entered the station a few paces behind each other.

Two of the boys are 13 and one is 14, prosecutors said. They turned themselves in to homicide detectives at the end of the week.